#include <iostream>
using namespace std;
#include <iomanip>
using std::setw;
#include <cmath>

int main()
{
	double a[2];
	while(1)
	{
		cin >> a[0];
		cin >> a[1];
		if (a[0]==a[1]) break;
		else
		{
			if (a[0]>a[1]) {
				cout << a[1] << "  "<< a[0] << "\n";
			}
			else
				cout << a[0] << "  "<< a[1] << "\n";
		 } 
	}
	return 0;
}
